What are the two forbidden islands in Hawaii?

Hawaii's two restricted islands are Niihau and Kahoolawe. Niihau, the westernmost inhabited Hawaiian island, is privately owned by the Robinson family and has been kept off-limits to outsiders since 1864. Only Native Hawaiians and invited guests may visit. Niihau Helicopters offers one-day hunting and snorkeling safaris to the island's uninhabited areas from around $375–485 per person — the only way for most tourists to access it. Kahoolawe, a small island south of Maui, was used as a US Navy bombing range from World War II until 1990. It's now a state reserve managed by the Kaho'olawe Island Reserve Commission for Native Hawaiian cultural restoration — no public tourism. Neither island offers standard tour access; Niihau is the only one with any visitor program.